When Ericsson Mobile set out in 1994 to develop the Bluetooth wireless standard, earpieces were one of the things that it first had in mind. Despite this, consumers haven't yet seen many Bluetooth audio devices that can reproduce full stereo sound. But that is starting to change. At CES this year there were a number of stereo headphones that promised to bring high-quality dual-channel sound to consumers. One such device is Bluetake's i-Phono Hi-Fi Sports Headphones.

Don't take these as just an expensive replacement for the cheap earbuds that come with most portable audio players today. We got a chance to give one a try, and found out that it has a couple of [more] tricks up its sleeve.

But before we get to the tricks, some background. The first question we had was: why are these devices just hitting the market now, when Bluetooth has been available to consumers since 1998? One expert on the CES floor explained that there have been two main obstacles: chip prices and data transmission rates. As Bluetooth has become more popular and its use more widespread, manufacturing costs have been on the decline, removing one problem. But obviously there hasn't been an increase in the amount of data that the 2.4 GHz band is able to carry. Even though the specification standard 1.2 is already in most devices crossing register counters today, manufacturers are still limited by a 1 Mbps data rate.